Pipe making machine

ABSTRACT

A machine for moulding pipe in an upright stationary mould having a cylindrical troweling element rotatable within the mould and axially moveable therein. Packing means directly above the troweling element have rollers to pack the moulding material into the space between the element and the mould. Deflector bars and closure plates adjacent the roller assure proper distribution of the material.

Umted States Patent 1 1 1111 3,776,677 Wilkinson Dec. 4, 1973 [54] PIPE MAKING MACHINE 2,641,818 6/1953 Eschenbrenner 425/262 3,091,013 5/1963 Robinson 425/262 X [751 Hmace Alla" P 3,096,556 7/1963 Woods 425/262 New South Wales, Australla [73] Assignee: Monier Research & Development Pty. Ltd., Villawood, New South Primary ExaminerJ. Spencer Overholser Wales, Australia Assistant Examiner-DeWalden W. Jones [22] Filed: Dec. 1971 Att0rney--R1chard K. Stevens et al.

[21] Appl. No.: 209,834

[30] Foreign Application Priority Data [57] ABSTRACT Dec. 24, 1970 Australia PA 3589 A machine for moulding pipe in an upright stationary [52] US. Cl 425/262, 425/356, 425/457 mould having a cylindrical troweling element rotatable 425/460 within the mould and axially moveable therein. Pack- 51 Int. Cl B28b 1/29 g means direetly above the troweling element have [58] Field of Search 425/262,,356, 457, rollers to p k h m ing material n the space 425/460 between the element and the mould. Deflector bars and closure plates adjacent the roller assure proper References Cited distribution of the material.

UNITED STATES PATENTS I l,862,709 6/1932 Schultz 425/262 3 Claims, 5 Drawing Figures PATENTEnnEc 41975 37765.

saw 1 or 2 PATENTED 41975 sum 2 BF 2 FIG.5.

PIPE MAKING MACHINE.

This invention relates to pipe making machines, and more particularly to machines for making concrete or ceramic pipes from mouldable material in upright moulds by means of a troweling element inserted therein and having 'a clearance with respect to the mould equal to the desired wall thickness of the pipe.

In known arrangements for the construction of concrete pipes, attempts have been made to pack the material admitted to the space between the troweling element and the mould by means of blades attached to the piston which progressively withdraws the troweling element from the mould while causing said troweling element to rotate and thereby smooth the inner surface of the formed pipe. This packing action has also been performed by rollers mounted upon axes substantially parallel with said piston and extending beyond the periphery of said troweling element. Both said arrangements have been adapted to smooth and pack the material of 2 the formed pipe radially in an outward direction.

The above arrangements have not been satisfactory in providing a sufficiently dense pack, and in accordance with the invention therefore, a pipe making machine comprises means wherein blades of the abovedescribed kind are adapted to pack axially in a downward direction upon the upper or free end of the formed pipe so that the smoothing action of the inner wall of said pipe is performed only by said troweling element.

Certain embodiments of the invention will now be described with reference to the accompanying drawings in which similar references indicate corresponding parts, and in which:

FIG. 1 shows in front elevation and partly in section,

a pipe making machine employing blades as a packing means,

FIG. 2 shows in front elevation an arrangement of rollers which may be substituted for said blades,

FIG. 3 shows a modification of the arrangement of FIG. 2 in which a flat bar precedes each roller,

FIG. 4 shows in elevation a view along the line 4-4 of FIG. 3, and

FIG. 5 shows in elevation a detail of the arrangement of FIG. 4.

Upon referring to the drawings it will be seen that blades 6 have their periphery running as close to the mould 7 as practicable while still maintaining a clearance between the blades and the mould.

A guidance system 8 contains means whereby a troweling element 9 attached to the shaft 10 is rotated with respect to the mould 6 by motors such as 14, geared to the carrier 15, so as to form the pipe 11 from the material 12 which is admitted through the throat 13 of said mould. As the pipe is formed, the troweling element 9 stronger than in prior systems even when made from 65 the same material. Furthermore, the invention is suitable for the formation of ceramic pipes as wellas. the concrete pipes made in prior systems. A pipe constructed from densely packed material is desirable in those applications where it is necessary for the pipe to be impervious to liquids transmitted or held therein, and a further advantage of such a pipe is that it is more easily stripped from the mould in its green state prior to curing.

Preferably, the troweling element 9 and the blades 6 are rotated in opposite senses (owing to suitable gearing of the carriers 15 and 18 to respective motors l4 and 19) in order to reduce torsional stresses upon a frame which supports the movable parts of the pipe making machine.

In a modification of the invention shown in FIG. 2, said blades are replaced by a set of frusto-conical rollers such as 20 whose working line of contact lies in a radial plane with respect to the shaft 10. Such rollers carry out a function similar to that of the blades 6, but less power is required for the packing operation and less heat is generated in thematerial of the formed pipe. Furthermore, the wear upon the surfaces of the rollers is less than upon blades constructed from similar materials.

In a further modification of the invention shown in FIGS. 3 to 5, a deflector bar such as 21 is mounted in front of each said roller 20 in its direction of rotation, said bar being tangential to the axis of the shaft 10 and adapted to just sweep the top of the troweling element 9. A closure plate 22 between the top of each said bar and the carrier 23 conforms closely with the rearward profile of each said roller to prevent pipe-forming material from passing behind the respective bar, and feed control slippers such as 24, fitted to the outer ends of respective feed control plates such as 25 are so shaped that the inner edge such as 26 of each said slipper conforms with the radius swept bythe outer edge of its associated roller, each said slipper being fitted with its lower face at a predetermined height above the paths of the roller face said height being determined by the amount of feed to the roller.

The invention in its various embodiments above described is suitable for the construction of concrete or ceramic pipes whose dimensions are of the order of,

drive shaft for rotating it and simultaneously raising it,

and packing means to pack mouldable material downwardly into the space between said mould and said element; said packing means comprising:

a. a carrier which concentrically surrounds said drive shaft above and adjacent said element;

b. means to rotate said carrier and maintain it immediately above said element;

c. a plurality of rotatably mounted frustro-concial rollers on said carrier and peripherally presented to the upper end of said space;

d. moulding material deflector bars mounted on said carrier in front of the rollers in the direction of carrier rotation, said bars being tangential to the axis of said carrier so to deflect moulding material towards the periphery of said carrier, and having for each deflector bar mounted on the outer end of its deflector bar and radially spanning said space with its lower face spaced above the lowermost point of its related roller by a distance corresponding the desired feed to the rollers.

2. A machine according to claim 1 wherein the means for rotating said drive shaft, and the means for rotating said carrier rotate in opposite directions.

3. A machine according to claim 1 wherein said rollers are three in number and are uniformly spaced around the axis of said carrier.

I It i 

1. A pipe moulding machine of the kind having an upright stationary mould, a cylindrical troweling element concentrically rotatable within and axially moveable through said mould towards the upper end thereof, a drive shaft having said element concentrically fixed on its lower end, means applied to the upper end of said drive shaft for rotating it and simultaneously raising it, and packing means to pack mouldable material downwardly into the space between said mould and said element; said packing means comprising: a. a carrier which concentrically surrounds said drive shaft above and adjacent said element; b. means to rotate said carrier and maintain it immediately above said element; c. a plurality of rotatably mounted frustro-concial rollers on said carrier and peripherally presented to the upper end of said space; d. moulding material deflector bars mounted on said carrier in front of the rollers in the direction of carrier rotation, said bars being tangential to the axis of said carrier so to deflect moulding material towards the periphery of said carrier, and having their lower edges spaced from the upper face of said element just sufficient to provide mechanical clearance therebetween; e. a closure plate for each of said deflector bars secured by its leading edge to the top of its deflector bar, and having its trailing edge shaped in close conformity with the inner profile of its rolleR and the adjacent portions of said carrier, thereby to deter moulding material from passing to the rear of its deflector bar; and f. means to control the amount of moulding material fed to the rollers comprising a feed control slipper for each deflector bar mounted on the outer end of its deflector bar and radially spanning said space with its lower face spaced above the lowermost point of its related roller by a distance corresponding the desired feed to the rollers.
 2. A machine according to claim 1 wherein the means for rotating said drive shaft, and the means for rotating said carrier rotate in opposite directions.
 3. A machine according to claim 1 wherein said rollers are three in number and are uniformly spaced around the axis of said carrier. 